Screen panel



Dec. 6, 1966 w. E. BIXBY SCREEN PANEL Filed April 27, 1964 INVENTOR. Wild/K65. 50(5) United States Patent 3,289,837 SCREEN PANEL Wallace E. Bixby, Gas St. at Nickel Plate Railroad, Wellington, Ohio Filed Apr. 27, 1964, Ser. No. 362,663 Claims. (Cl. 2139-395) This invention relates to a screen panel and more particularly to screen panel constructions of the type which undergo vibration in use. I

United States Patent No. 2,690,265, issued toWallace E. Bixby on September 28, 1954, discloses a screen panel employing elongate wire elements looped about successive of spaced transversely disposed cross rods. The wire elements are triangular or wedge shaped with their bases extending longitudinally along the top plane of the screen panel. This type of screen panel made entirely from steel has proved very effective and advantageous when mounted upon vibrating equipment commonly used in washing or screening ore materials or the like, the screen panels permitting particles up to a predetermined maximum size to pass therethrough.

Because the screen panels are intended for use in vibrating machines, the panels are usually made in quite narrow widths to minimize fiexure of the support rods and consequent frictional wear in the contact areas between the wire elements and the cross rods. It is believed that flexure of the support rods produces fatigue cracks in the support rods and that simultaneously occuring frictional wear at the fatigue cracks in the areas of contact with the wire elements accelerates the approach of breakdown due to fatigue. To deter such breakdown in relatively wide screen panels, added longitudinally extending support structures have been used in such manner as to minimize cross rod flexure in the unsupported widths thereof. Such added structures are found to be relatively ineffective, however, especially with heavy loads.

An object of this invention, therefore, is to provide a screen panel construction enabling the use of panels having relatively large unsupported widths.

A more specific object of this invention is to provide members integral with the screen construction limiting the cross rod flexure at the areas of the screen which are most adversely effected by vibration.

Other objects and advantages will become more apparent from the following description.

Referring to the drawings, in which like numbers refer to like parts:

FIGURE 1 is a perspective view of a section of a screen panel made in accordance with this invention.

FIGURE 2 is a side elevational view, with portions in cross-section, of the screen panel of FIGURE 1.

FIGURE 3 is a plan view of the screen panel employing a modified and presently preferred construction made in accordance with this invention.

FIGURE 4 is a longitudinal sectional view of a portion of the panel of FIGURE 3 taken along line 4-4 of FIGURE 3.

FIGURE 5 is a transverse cross-sectional view of a portion of the screen panel of FIGURE 3 taken along line 55 thereof.

Referring to FIGURE 1 in greater detail, a screen panel is shown comprising a plurality of longitudinally extending parallel wire elements 12 supported by a plurality of substantially coplanar, parallel cross rods 14 disposed in substantially equally spaced relation beneath the wire elements 12'and extending transversely thereof. Each of the wire elements 12 has downwardly looped portions 16 encircling each successive cross rod 14. The wire elements 12 may be generally circular in cross-section at the looped portion 16 thereof. Otherwise, they may have a triangular cross-section as illustrated in the portions thereof which span the cross rods 14. The bases of the triangular portions of the rods 14 face upwardly to form the top surface of the screen panel 10.

The wire elements 12 are confined between any suitable spaced abutment members on the cross rods 14. As illustrated in FIGURE 1, the abutments may comprise enlarged ends of the rods 14 formed by peening the end portions thereof over the internal margins of the looped portions 16 of the outermost wire elements 12. As will be apparent to those skilled in the art, various other abutment structures could be used. Also spacers (not shown) could be inserted between the looped portions 16 of the various wire elements 12 to increase the spacing therebetween. Further, a supporting frame (not shown) may be attached to the cross rods 14 at any desired location to adapt the screen panel 10 for mounting in a vibrating mechanism.

When the screen panel 10 undergoes vibration under load, there is a degree of transverse vibration of the individual wire elements 12. Such vibration is tolerated, in fact desired, in most screening operations because the independent wire movements retard screen blinding. However, flexure of the transverse cross rods 14 has been found most undesirable, especially in wide screen panels. Both the wire elements 12 and the cross rods 14 are made from steel. Because the diameter of the wire elements 12 is relatively small, they have an abrading effect, leading to failure of the cross rods 14. Internal cracks have been detected in the rods 14 emanating from the contact points of the wire elements 12 and the rods 14 after short usage. Early fatigue and associated abrasion of the cross rods 14 severely limits the useful life of the screen panel 10.

In accordance with this invention, means are provided to minimize the flexure of the cross rods 14 and associated wear with the looped portions 16 of the wire elements 12.

In FIGURE 2, such means comprises a plurality of elongate, hollow tubes 18 made from a bearing material other than steel, preferably nylon, said tubes encircling the rods 14 and being tightly sandwiched between the looped portions 16 of the wire elements 12 and the rods 14. Desirably, the tubes 18 extend the entire length of the rods 14. The primary purpose of the tubes 18 is to reduce the fiexure and associated effects mentioned above. To this end, the tubes 18 not only add to the diameter of the rods 14, reducing their transverse fiexure, but also render the union between the rods 14 and the loops 16 more rigid by eliminating any gaps therebetween. The coefficient of friction between nylon and steel is relatively low. Hence, abrasion of rods 14 is eliminated or minimized. Further, the tubes 18 aid the rods 14 in supporting heavier loads than could be supported by other light weight screen constructions. It will be recognized by those skilled in the art that other materials having low friction against steel can be substituted for the nylon, an example being Teflon.

Referring to FIGURES 3, 4 and 5, another construc tion is shown which also serves to reduce flexure of the support rods. FIGURE 3 discloses an entire screen panel 10 employing wire elements 12 having looped portions 16 extending downwardly and encircling a plurality of substantially equally spaced cross rods 14. A pair of rubber cushions 20 extend longitudinally along the side margins of the panel 10. The cushions 20 are apertured at spaced intervals to receive the ends of the rods 14. As will be more apparent below, the abutment means confining the wire elements 12 in predetermined spaced relationship on the rods 14 may comprise end spacers, which in turn are confined on the rods 14 by peening the ends of the rods 14, or by welding. The rubber cushions 20 illustrated in FIGURES 3, 4 and 5 are of the type commonly used as adapters for mounting screen panels on supports or decks forming part of the vibrating machine in which the panels are incorporated.

A plurality of supplementary support members 22 extend transversely of the wire elements 12 in parallel relationship to the rods 14. Most desirably, there is one supplementary support member 22 immediately adjacent each rod 14 and alternating therewith beneath the wire elements 12. The supplementary support members 22 each comprise transverse supplementary, steel cross rods 24 having spacer sleeves 26 at the opposite ends thereof (see FIGURE received within apertures in the cushion 20. The ends of the rods 24 may be peened over, as illustrated at 28, to confine the spacers 26 thereon. As mentioned above, similar spacers may be mounted on the ends of the cross rods 14.

Mounted on each rod 24 between the spacers 26 is a vibration damping member comprising a tubular, resilient snubbing member 30. The member 30 on each supplementary cross rod 24 extends substantially the entire length thereof and across the entire spanof the wire elements 12. As shown best in FIGURES 4 and 5, the members 30 serve both to support the wire elements 12 and also to reduce the vibration of the wire elements 12 in the area of the looped portions 16. To this end, the periphery of the members 30 engage both against the looped portions 16 of the wire elements 12 and against the lower surfaces of the straight portions of the wire elements 12 adjacent the cross rods 14. Because of the engagement between the members 30 and the wire elements 12, The transverse vibrations of the elements 12 are considerably reduced adjacent the cross rods 14. In addition, the supplementary support members 22 will damp or suppress flexure of the cross rods 14. Thus, the vibrations imparted to the load on the screen by operation of the associated vibrating machine will produce increasing and decreasing loads on the screen with resulting flexure and relaxation of the cross rods 14. The supplementary members 22 restrict such bending movements. As illustrated in FIGURE 4, the supplementary cross rods 24 may be of larger diameter than the cross rods 14 to facilitate such function. In practice, the mounting of supplementary support members 22 having snubbing members 30 made of rubber adjacent the cross rods 14 has resulted in screen panels having a useful life of more than twice that of screen panels without such structure.

Although two embodiments of the invention have been described in detail, it will be understood that various changes may be made within the scope of this invention as defined in the appended claims Having thus described my invention, I claim:

1. A screen panel including: a plurality of longitudinal screen elements; a plurality of cross members; means connected to at least some of said cross members confining the longitudinal screen elements thereon, each of said screen elements being looped about at least some of said cross members; and vibration dampeners supported by and encircling at least some of said cross members, said vibration dampeners engaging and partially supporting said screen elements.

2. A screen panel including: a plurality of longitudinal wire elements; a plurality of parallel cross rods disposed beneath and transversely to said wire elements; said wire elements having portions looped downwardly about at least some of said cross rods; means connected to at least some of said cross rods confining the wire elements thereon; a plurality of vibration dampener members, there being one vibration dampener member encircling each of at least some of said cross rods and extending the entire length thereof, said vibration dampener members engaging portions of each of the looped portions in said wire elements. I

3. The screen panel of claim 2 wherein said vibration dampener members comprise a plurality of hollow tubes, there being one tube encircling each of said cross rods and wherein the looped portions of said wire elements snugly engage the outer surfaces of said tubes, said wire elements and said cross members being made of steel and said tubes being of a material having a low coefiicient of friction with respect to steel.

4. The screen panel of claim 2 wherein said wire elements are looped about substantially equally spaced, alternate cross rods, said vibration dampener members being mounted on the remaining cross rods, and wherein said vibration dampener members comprise resilient tubes encircling said remaining cross rods.

5. A screen panel including a plurality of longitudinal wire elements, a plurality of parallel cross rods disposed beneath and transversely of said wire elements, said wire elements having portions looped downwardly about said cross rods, abutment means connected to said cross rods confining said wire elements thereon, at least one supplementary cross rod extending beneath said wire elements and parallel to said first mentioned cross rods, a tubular, resilient vibration dampener member encircling said supplementary cross rod, and means supporting said supplementary cross rod in fixed position adjacent one of said first mentioned cross rods with said vibration dampener member engaged with said wire elements.

References Cited by the Examiner UNITED STATES PATENTS 3,037,630 6/1962 Bixby 209393 3,155,441 11/1964 Bemmann a 209-449 X 3,247,966 4/1966 Harmon a 209-395 HARRY B. THORNTON, Primary Examiner.

L. H. EATHERTON, Assistant Examiner. 

2. A SCREEN PANEL INCLUDING: A PLURALITY OF LONGITUDINAL WIRE ELEMENTS; A PLURALITY OF PARALLEL CROSS RODS DISPOSED BENEATH AND TRANSVERSELY TO SAID WIRE ELEMENTS; SAID WIRE ELEMENTS HAVING PORTIONS LOOPED DOWNWARDLY ABOUT AT LEAST SOME OF SAID CROSS RODS; MEANS CONNECTED TO AT LEAST SOME OF SAID CROSS RODS CONFINING THE WIRE ELEMENTS THEREON; A PLURALITY OF VIBRATION DAMPENER MEMBERS, THERE BEING ONE VIBRATION DAMPENER MEMBER ENCIRCLING EACH OF AT LEAST SOME OF SAID CROSS RODS AND EXTENDING THE ENTIRE LENGTH THEREOF, SAID VIBRATION DAMPENER MEMBERS ENGAGING PORTIONS OF EACH OF THE LOOPED PORTIONS IN SAID WIRE ELEMENTS. 